A tolerance to wet etching is an important factor for a material layer that is used as a spacer of a semiconductor device. However, the tolerance to wet etching may be degraded when an unnecessary component of a precursor remains within the material layer. In obtaining minute patterns, the use of a material susceptible to high temperatures has been increasing. When a material layer is formed at certain temperatures, electrical characteristics or a physical property, such as etching resistance, may not be met.